Erik Moeller wrote:
The most difficult part of the implementation is probably the captcha itself.
If LiveJournal have done it, surely MediaWiki can?
I would be strongly opposed to requiring captchas for all logins, even those which do not come from open proxies, because a visual captcha would exclude blind people from accessing Wikipedia.
LiveJournal's captcha includes the option to take an audio test.
Timwi